Abstract: Based on the externality characteristics of provincial border areas, this paper uses hand-collected data of listed companies' geographic information, environmental investment data and green innovation data to examine the relationship between companies' border location and their environmental performance. The paper finds that compared with enterprises located in inland areas, enterprises in border areas show a poor environmental performance, and this negative relationship is more significant in hilly and mountainous areas, areas with abundant natural resources and lakes across provincial boundaries. Further analysis shows that resource constraints and lack of supervision are important reasons for the poor environmental performance of enterprises in border areas; the improvement of transportation facilities has a certain boundary breakthrough effect, which can alleviate the poor environmental performance of border enterprises in plain areas and areas with lakes across provincial boundaries. The paper enriches and expands the literature of boundary effect and enterprise environmental performance research, and has important implications for solving the imbalance of regional environmental development, achieving the goal of "carbon neutrality" and promoting the transformation of green innovation and high-quality development of enterprises.

Key words: provincial boundary, geographical endowment, firm environmental investment, firm green innovation